Information Technology Reference
In-Depth Information
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Figure.3 7
A drawing tablet.
Sensory Input
Many portable devices, such as smartphones and tablets, have new types of input technology that detect direc-
tion, motion, and/or location. For example, some devices have a global positioning system (GPS) to detect your
location, an accelerometer to tell how fast you are moving, a compass to report what direction you are facing,
and a gyroscope to report the orientation of the device. It is the gyroscope, for example, that tells a phone or
tablet when you turn it on its side so it can change the orientation of the screen.
Scanning Devices
A scanner
digitizes
hard-copy photos and documents and stores them
electronically. Scanners work by shining a bright light on the surface of the
page and measuring the amount of light that bounces back from it using
a photosensitive
charge-coupled device (CCD)
. Lighter areas bounce
back more light than darker areas. For color scanning, multiple sensors are
used, each one picking up a different color: red, green, and blue.
digitize
To convert something from hard-copy to
digital (computerized) form.
charge-coupled device (CCD)
The light-
sensitive sensor in a scanner that records the
amount of light bounced back from the image.
A scanner can be a stand-alone device, or it can be a component in a
multi-function device (MFD)
that com-
bines the functions of a printer, copier, and scanner into one unit.
NOTE
multi-function device (MFD)
A device that
combines the functions of a printer, a copier, and
a scanner into one unit, and also a fax in some
models.
Most scanners are
flatbed
models, as in Figure 3.8, where you place
the image on a flat piece of glass and then a sensor and light bar moves
beneath it to capture the image. A flatbed scanner may optionally have
a
document feeder
on it so multiple pages can be queued for scanning.
There are also smaller portable scanners that either feed in one sheet at a
time past a stationary sensor and light bar, or that you hold in your hand
and manually move across the image to be scanned.
flatbed scanner
A scanner that has a large flat
glass surface on which the page to be scanned
is placed.
document feeder
A mechanical feature of
some scanners that enables multiple pages to be
scanned consecutively without user intervention.
When you scan text, you can use optical character recognition (OCR)
software to convert the scanned image to text that you can work with in
a text editing program.
